If you want to restrict the class so that it can only be seen by one particular external assembly, you use internal to limit the scope to the current assembly, and then you implement InternalsVisibleTo[^] to link this to the specific assembly.

If you are using local computer to access using ip address there should not be any issue only if DNS entry is set to redirect on another page. Secondly check if firewall stop your ip address from accessing the site ?

First try to simply add html page and check if it is also not working with ip address ?